The localization of autophagy, apoptosis and necrosis in different regions of the midgut in <i>N</i>. <i>heteropoda</i>.

<p>The localization of autophagy, apoptosis and necrosis in different regions of the midgut in <i>N</i>. <i>heteropoda</i>.</p

Apoptosis in the <i>N</i>. <i>heteropoda</i> midgut.

<p>3D representation of the Tunel assay and Hoechst 33342 staining. Nuclei of apoptotic cells (red), nuclei (blue). Confocal microscope. <b>(A)</b> Fragment of the anterior region of the intestine. Bar = 9.5μm. <b>(B)</b> Fragment of the hepatopancreatic tubule. Bar = 11μm.</p

Autophagy in the <i>N</i>. <i>heteropoda</i> midgut.

<p><b>(A)</b> Hepatopancreas. TEM. Bar = 0.15 μm. <b>(B-D)</b> Intestine digestive cells. <b>(B)</b> TEM. Bar = 0.1 μm. <b>(C)</b> Mitophagy. TEM. Bar = 0.15 μm. <b>(D)</b> Mitophagy. TEM. Bar = 0.55 μm. <b>(E-F)</b> Hepatopancreas. <b>(E)</b> TEM. Bar = 0.75 μm. <b>(F)</b> TEM. Bar = 0.45 μm. Autophagosomes (au), autolysosomes (al), residual body (rb), cisterns of the endoplasmic reticulum (ER), mitochondria (m), microvilli (mv), midgut lumen (l), vacuoles (v), lamellar bodies (lb), lipids (l).</p

Autolysosomes and acid phosphatase localization in the <i>N</i>. <i>heteropoda</i> midgut.

<p><b>(A)</b> Transverse section through the intestine with pink spots of acid phosphatase localization. Midgut lumen (l), midgut epithelium (e). Acid phosphatase staining. Light microscope. Bar = 20 μm. <b>(B)</b> Transverse section through the hepatopancreatic tubule with pink spots of acid phosphatase localization. Midgut lumen (l). Acid phosphatase staining. Light microscope. Bar = 30 μm. <b>(C)</b> Transverse section through the intestine. Negative control for acid phosphatase staining. Midgut lumen (l) midgut epithelium (e). Light microscope. Bar = 19 μm. <b>(D)</b> Intestine. Electron-dense autolysosomes (al), mitochondria (m), cisterns of ER (ER), microvilli (mv). Acid phosphatase staining. TEM. Bar = 0.8 μm. <b>(E)</b> Hepatopancreas. Electron-dense autolysosomes (al), cisterns of ER (ER). Acid phosphatase staining. TEM. Bar = 0.8 μm. <b>(F)</b> 3D representation of the accumulation of lysosomes and autolysosomes (red signals). Nuclei (blue signals). A fragment of the intestine. LysoTracker Red and Hoechst 33342 staining. Confocal microscope. Bar = 10.5μm. <b>(G)</b> 3D representation of the accumulation of lysosomes and autolysosomes (red signals). Nuclei (blue signals). A fragment of the proximal zone of the hepatopancreas. LysoTracker Red and Hoechst 33342 staining. Confocal microscope. Bar = 10μm.</p

Autophagosomes formation in the <i>N</i>. <i>heteropoda</i> midgut.

<p><b>(A)</b> Cells of the proximal zone of the hepatopancreatic tubules. TEM. Bar = 0.55 μm. <b>(B-C)</b> Intestine digestive cells that showed signs of autophagy. TEM. <b>(B)</b> Bar = 0.4 μm. <b>(C)</b> Bar = 0.5 μm. <b>(D)</b> Hepatopancreatic epithelial cell that showed signs of autophagy. TEM. Bar = 0.45 μm. Cisterns of the endoplasmic reticulum (ER), mitochondria (m), vesicles with electron-dense content (v), autophagosomes (au), agglomerations of degenerating organelles (asterisks), phagophore formation (arrows).</p

Ultrastructural features of apoptotic cells in the <i>N</i>. <i>heteropoda</i> midgut.

<p><b>(A-C)</b> Intestine. TEM. <b>(A)</b> Electron-dense cytoplasm of an apoptotic cell (ac). Distinct extracellular spaces (arrows) between the apoptotic and neighboring digestive cells (dc). Bar = 1.7 μm. <b>(B-C)</b> Lobular shaped nucleus (n) with patches of heterochromatin. <b>(B)</b> Bar = 1 μm. <b>(C)</b> Bar = 1.2 μm. <b>(D-E)</b> Hepatopancreas. TEM. <b>(D)</b> Apoptotic cell (ac) losing contact with the basal lamina (bl). Bar = 1.5 μm. <b>(E)</b> Apoptotic cell (ac) discharged into the midgut lumen (l). Bar = 2 μm. Cisterns of ER (ER), vacuoles (v), mitochondria (m), nucleus (n), nucleolus (nu), basal lamina (bl).</p

Percentage [%] of cells in the entire intestine and proximal zone of the hepatopancreatic epithelium in <i>N</i>. <i>heteropoda</i> that showed signs of autophagy.

<p>Percentage [%] of cells in the entire intestine and proximal zone of the hepatopancreatic epithelium in <i>N</i>. <i>heteropoda</i> that showed signs of autophagy.</p

Necrosis in the <i>N</i>. <i>heteropoda</i> midgut.

<p><b>(A)</b> Intestine. TEM. Bar = 1 μm. <b>(B)</b> Hepatopancreas. TEM. Bar = 0.9 μm. Necrotic cell (nc) with electron-lucent cytoplasm, midgut lumen (l), digestive cells (dc) of the intestine, mitochondria (m), microvilli (mv), cisterns of ER (ER).</p

Percentage [%] of necrotic cells in the entire intestine and proximal zone of the hepatopancreatic epithelium in <i>N</i>. <i>heteropoda</i>.

<p>Percentage [%] of necrotic cells in the entire intestine and proximal zone of the hepatopancreatic epithelium in <i>N</i>. <i>heteropoda</i>.</p

Structure and Ultrastructure of the Endodermal Region of the Alimentary Tract in the Freshwater Shrimp <i>Neocaridina heteropoda</i> (Crustacea, Malacostraca)

<div><p>The freshwater shrimp <i>Neocaridina heteropoda</i> (Crustacea, Malacostraca, Decapoda) originates from Asia and is one of the species that is widely available all over the world because it is the most popular shrimp that is bred in aquaria. The structure and the ultrastructure of the midgut have been described using X-ray microtomography, transmission electron microscopy, light and fluorescence microscopes. The endodermal region of the alimentary system in <i>N</i>. <i>heteropoda</i> consists of an intestine and a hepatopancreas. No differences were observed in the structure and ultrastructure of males and females of the shrimp that were examined. The intestine is a tube-shaped organ and the hepatopancreas is composed of two large diverticles that are divided into the blind-end tubules. Hepatopancreatic tubules have three distinct zones – proximal, medial and distal. Among the epithelial cells of the intestine, two types of cells were distinguished – D and E-cells, while three types of cells were observed in the epithelium of the hepatopancreas – F, B and E-cells. Our studies showed that the regionalization in the activity of cells occurs along the length of the hepatopancreatic tubules. The role and ultrastructure of all types of epithelial cells are discussed, with the special emphasis on the function of the E-cells, which are the midgut regenerative cells. Additionally, we present the first report on the existence of an intercellular junction that is connected with the E-cells of Crustacea.</p></div